1. Field of the Invention
The present invention relates to a measuring apparatus, such as an oscilloscope and a spectrum analyzer, for measuring a time characteristic and a frequency characteristic of an electrical signal and a frequency-dependent characteristic of an optical component.
2. Description of the Related Art
Generally, in a measurement using a measuring apparatus, such as an oscilloscope and a spectrum analyzer, for measuring a time characteristic and a frequency characteristic of an electrical signal and a frequency-dependent characteristic of an optical component, which apparatus is adapted to show a waveform indication representing a result of a measurement on a screen of a display unit, grids and markers are used in order to accurately know a result of a measurement performed at a certain point.
Grids in the measuring apparatus are lines for dividing an axis of ordinates and/or an axis of abscissas at predetermined intervals so as to facilitate the reading of a waveform that represents a result of a measurement by the reading apparatus and that is indicated on the screen of the display unit.
Further, markers are used for designating arbitrary positions on a waveform representing a result of a measurement, which is shown on the screen of the display unit, and for indicating the values of ordinates and/or abscissas of the positions.
Hitherto, measurement has been performed by indicating the grids and the markers together with a waveform, which represents a result of the measurement, on the screen of a display unit. According to a conventional method of setting a marker thereon, the marker can be moved by using a rotary knob or a cursor key. Moreover, the interval, by which the marker moves by 1 step, can be narrowed or broadened. However, the interval, by which the marker moves by 1 step, cannot be arbitrarily changed at each step.
Furthermore, according to a conventional method of setting the interval between grids, the interval therebetween is determined at a specific value but cannot be set at an arbitrary value.
The conventional methods of setting grids and/or markers cannot be applied to the case that it is continuously determined whether or not the quality of a signal source having an output, in which peak signals appear at predetermined wavelengths, is good, or whether or not the quality of a DUT (Device Under Test) having output spectra, in which absorption spectrum and transmission spectrum occur at predetermined wavelengths, is good, as illustrated in FIG. 1.
In the case that the moving interval of the marker is not equal to the interval between the peaks, as shown in FIG. 1, the conventional methods need to operate the rotary knob or the cursor key at each reading of a peak value to thereby move the marker so that the position of the marker coincides with the position corresponding to the peak value, and thereby compare the position, at which the signal is actually measured, with that, at which the signal originally should appear.
An object of the invention is to achieve easy determination and analysis of results of a measurement and to provide a method for arbitrarily change predetermined intervals between grids and predetermined moving interval of a marker on a screen of a display unit.
To achieve the foregoing object, according to an aspect of the invention, there is provided a method (hereunder referred to as a first method of the invention) of setting grids and/or markers on the screen of a display unit of a measuring apparatus, which comprises the steps of changing a mode of the apparatus into a mode of setting the grids and/or the markers, setting the grid and/or the marker serving as a reference, and setting a plurality of grids and/or markers, each of which provides an arbitrary interval with respect to the grid and/or the marker serving as the reference.
Incidentally, in the present specification, the expression xe2x80x9cgrids and/or markersxe2x80x9d is used for indicating both the cases that only grids or only markers are set, and that both the grids and the markers are set.
Further, according to an example (hereunder referred to as a second method of the invention) of the first method of the invention, the step of setting a plurality of grids and/or markers, each of which provides an arbitrary interval with respect to the grid and/or the marker serving as the reference includes the step of designating positions of individual grids and/or markers by using a rotary knob or a cursor key. Thus, an operator can arbitrarily change the intervals between the grids and/or the interval between the markers on the screen of the display unit. Consequently, the determination and analysis of results of a measurement, which are displayed on the screen of the display unit, can easily be performed.
Moreover, according to another aspect of the invention, there is provided a method (hereunder referred to as a third method of the invention) of setting grids and/or markers on a screen of a display unit of a measuring apparatus, which comprises the steps of changing a mode of the apparatus into a mode of setting the grids and/or the markers, inputting data representing a setting range, in which grids and/or markers are set, on the screen of the display unit, and inputting a division number corresponding to the setting range, in which grids and/or markers are set. Thus, in the setting range, the grids and/or the markers can easily be set at equal intervals.
Further, according to an example (hereunder referred to as a fourth method of the invention) of the third method of the invention, the setting range is set over the entirety of the screen of the display unit. Thus, the grids and/or the markers can easily be set at equal intervals over the entire screen of the display unit.
Furthermore, according to an example (hereunder referred to a fifth method of the invention) of the third or fourth method of the invention, at the step of inputting data representing a setting range, in which grids and/or markers are set, on the screen of the display unit, the operator can designate the setting range by using a rotary knob or a cursor key.
Moreover, according to an example (hereunder referred to as a sixth method of the invention) of one of the third to fifth methods of the invention, at the step of inputting data representing a setting range, in which grids and/or markers are set, on the screen of the display unit includes the step of setting the data by inputting a numerical value from a ten key, and at the step of inputting a division number corresponding to the setting range, in which grid and/or markers are set, the division number can be set at a numerical value inputted from the ten key.
Furthermore, according to an example (hereunder referred to as a seventh method of the invention) of one of the first to sixth methods of the invention, the measuring apparatus is a spectrum analyzer indicating signal strength corresponding to a wavelength or a frequency. Thus, the determination and analysis of the result of the measurement, which is displayed on the screen of the display unit, can easily be performed.